JP-2002-310294A shows an electric driven shift range switching apparatus. In this shift range switching apparatus, an electric actuator is comprised of an electric motor and a reduction gear. An output shaft of the electric actuator is connected to a control rod of a shift range switching mechanism. The electric motor is energized to rotate the control rod to switch an actual shift range. A motor controller controls a rotation of the electric motor. The driving force of the motor is transferred from the output shaft to the control rod in order to change the actual shift range position. When the set shift range position is changed by use of a shift range set means (a manual set means), the motor controller controls the electric motor in such a manner that the recognized shift range position is consistent with the set shift range position so that the actual shift range position is switched.
The electric driven shift range switching apparatus is designed so that the shift range set means is not mechanically connected to the shift range switching mechanism and an operation (movement) of the electric actuator corresponds to an operation (movement) of the shift range switching mechanism. Specifically, it is designed that the rotor angle of the motor that the motor controller recognizes corresponds to the actual shift range position, or the output shaft angle that the motor controller recognizes corresponds to the actual shift range position.
However, since the electric actuator and the shift range switching mechanism have mechanical portions, the rotor angle (or output shaft angle) and the actual shift range may be not consistent with each other perfectly due to manufacturing errors and the like, which may cause a deviation therebetween. This deviation may deteriorate an accuracy of control of the shift range switching mechanism with the electric actuator.